In the prior art it is known to use a device for converting the wavelength of electromagnetic radiation comprising a conversion layer, wherein the conversion layer is configured to at least partly convert the wavelength of incident electromagnetic radiation. In particular, such devices are used to convert short-wave emission of an LED at least partly to a longer wavelength in order to generate white light, for example. High evolution of heat may occur in this case, such that good dissipation of heat from the conversion layer is advantageous.